The usual cylinder lock using transverse tumblers can be picked by inserting the appropriate tool into the key slot and manipulating the tumblers. My invention makes such lock-picking difficult or impossible by making the key very thin and using two opposing sets of tumblers so that the space between the mating pairs of tumblers when the lock is ready to open is very small. This space is also very tortuous so that ordinary picking tools cannot be used.
The prior art shows a key having a zig-zag portion that is only a part of a more complicated key and operated on only one set of tumblers located on one side of the key. If there is only one set of tumblers to one side of the key, the lock can be picked in the conventional way, since the tool that is used for picking such a lock can be inserted on one side of the tumblers and push them over, to thus position the tumblers to open the lock.
It is an object of this invention to provide a lock that is more difficult to pick than prior art locks.
Another object of the invention is to provide a pickproof lock that is low in cost, yet is satisfactory in use.